The purpose of this population-based study is to identify and compare both inter- and intra-generational factors that may affect periodontal health. Extensive medical and dental information is already available for a cohort of elderly adults being followed in the longitudinal Duke Piedmont Health Study and Piedmont 65+ Dental Study (P65). The proposed study will continue to include this probability sample of seniors and use them as probands (Gl) to select a sample of their sons, daughters, and grandchildren (the second [G2] and third [G3] generations ), and the other parents of these G2 and G3. The main epidemiologic study will consist of 660 Gl, 1,176 G2, and 113 G3. Families where Gl has advanced periodontitis will be oversampled. Dental exams that include detailed periodontal evaluation, personal interviews, and collection of plaque and blood samples will be performed in the subjects' homes. The major aims are to correlate the periodontal health status of Gl and G2 and to explore inter-generational factors that may explain periodontal health status. From studies in North Carolina since 1960, it is apparent that the prevalence of periodontal disease (PD) in blacks has been increasing. Substantial racial differences in PD exist that have not been sufficiently explained by other analyses. From the P65, it is known that large numbers of both biological and nonbiologic children were raised by Gl. By examining both types of children, and comparing them with their parents, familial and environmental relationships can be explored for each racial group. Based on epidemiologic, medical, social, behavioral, microbiologic and other explanatory data to be collected, the periodontal health status of the G2 and subsets of G2 (e.g., blacks vs. whites) can be examined after controlling for confounding factors. To explore mechanisms that may explain how PD is transmitted, DNA fingerprinting technics will be used to explore similarities among strains of bacteria within families. This study will incorporate many explanatory variables identified by different disciplines as playing a role in PD into a unified model. It is likely that some of these variables have not been studied together previously. Studying these multivariate relationships may increase our ability to identify individuals at risk of advanced PD.